An Approximate Calculation Method for the Average Infrared Radiation Intensity in the Rear Hemisphere of Serpentine 2D Exhaust Systems Based on Limited Data

Approximate computational methods were developed to determine the infrared radiation (IR) distribution and average IR intensity in the rear hemisphere of the serpentine two-dimensional (2D) exhaust system. These methods use data from horizontal and vertical detection planes. The methods were verified using the IR intensity data on the typical detection planes of the serpentine 2D convergent and convergent-divergent exhaust systems, respectively. The results demonstrate that the methods developed in this paper for calculating the distribution of IR intensity and the average IR intensity of the serpentine 2D exhaust system in the rear hemisphere are feasible. An approximate evaluation of the infrared stealth performance of the exhaust system can be conducted. According to the validation model presented in this study, the calculation error of the average IR intensity of serpentine 2D exhaust systems in the rear hemisphere is less than 5%, thereby satisfying the criteria for engineering applications.